Mar 132011
 

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General Information: Wikipedia entry

Cardiovascular

Studied Uses: Stroke

Studied Risks: Heart attack; high blood pressure

Coffee - Cardiovascular Evidence Summary - http://sheet.zoho.com

Overall Cardiovascular Score: -1.39

Behind the Score: The score is more complex than it appears at first glance. Case-control studies show increased risk for heart attack and ischemic stroke, particularly in the hour after consumption, among infrequent drinkers of coffee 1, and among those with risk factors for heart disease 2 3 or who are carriers of the “slow *1F allele” of the CYP1A2 gene, which produces slow caffeine metabolism. 4 Other negative effects on the score stem from studies showing a modest increase in blood pressure among coffee drinkers 5 and an increased risk of developing high blood pressure for those with the slow *1F allele. 6

On the other hand, large prospective cohort studies that spanned many years identified health benefits as well, mainly related to reduced relative risk for stroke 7, especially cerebral infarction 8 but also possibly subarachnoid hemorrhage 9. These benefits accrued over the long term among regular drinkers of more than 1 cup per day. Benefits seemed to attenuate at more than 2 cups per day, with other risks — such as risk for heart attack — possibly increasing at 3 cups per day. 10 It is important to note that prospective cohort studies are not randomized clinical trials, and some may rely on participants’ self-reported intake of coffee.

Notably, at least one prospective cohort study showed that tea appeared similarly effective at lower intake levels (2 cups a day). 11 Also, tea did not appear to raise stroke risk in the hour after consumption. 12

A 2008 prospective study of more than 120,000 people identified 13 a small reduction in all-cause mortality due to coffee consumption; however, this appears to be due to a “moderate” reduction in deaths from cardiovascular disease. Further study would be required to confirm this association.

Warnings and Special Notes: Based on study results, people with existing risk factors for heart disease may want to consult their doctor about the right level of coffee consumption for them.

What Now? An overarching review of coffee’s short- and long-term studied effects states that, “…. longer-term trials on the effects of coffee on biological risk factors are needed to bridge the gap in the data between short-term trials and cohort studies.” 14

What Can I Do? Coffee is readily available, if you choose to drink it. Because of pesticide use on conventional coffee crops 15, organic coffee may be worth the extra cost. Buying Fair Trade may reduce the risk of supporting exploitative producers.

Notes:

  1. Coffee and acute ischemic stroke onset: the Stroke Onset Study. Neurology, 2010.
  2. Transient Exposure to Coffee as a Trigger of a First Nonfatal Myocardial Infarction. Epidemiology, 2006.
  3. Coffee and alcohol consumption as triggering factors for sudden cardiac death: case-crossover study. Croatian Medical Journal, 2005.
  4. Coffee, CYP1A2 genotype, and risk of myocardial infarction. Journal of the American Medical Association, 2006.
  5. Blood pressure response to chronic intake of coffee and caffeine: a meta-analysis of randomized controlled trials. Journal of Hypertension, 2005.
  6. CYP1A2 genotype modifies the association between coffee intake and the risk of hypertension. Clinica Medica, University of Padova, 2009.
  7. Coffee consumption and risk of stroke in women. Circulation, 2009.
  8. Coffee and tea consumption and risk of stroke subtypes in male smokers. Stroke, 2008.
  9. Coffee Consumption and Risk of Stroke in Women. Stroke, 2011.
  10. Alcohol, smoking, coffee and risk of non-fatal acute myocardial infarction in Italy, European Journal of Epidemiology, 2001.
  11. Coffee and tea consumption and risk of stroke subtypes in male smokers. Stroke, 2008.
  12. Coffee and acute ischemic stroke onset: the Stroke Onset Study. Neurology, 2010.
  13. The relationship of coffee consumption with mortality, Annals of Internal Medicine, 2008.
  14. Coffee Consumption and Coronary Heart Disease: Paradoxical Effects on Biological Risk Factors versus Disease Incidence, Clinical Chemistry, 2008.
  15. Coffee, Conservation, and Commerce in the Western Hemisphere, Natural Resources Defense Council

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